1. Field of the Invention
The present invention is related to a system and method for digitally signing electronic documents.
2. Description of Related Art
The digital signature uses a hash algorithm and a public key cryptogram algorithm to encrypt and decrypt electronic documents. The hash algorithm (such as SHA1) is used for transforming the electronic document into a fixed-length character string that is usually 128 bit, 160 bit, 256 bit, and 512 bit, in order to shorten the length of the digital signature and improve the digital signature efficiency.
The public key cryptogram algorithm (such as RSA and ECC), also known as asymmetry algorithm, is used for encrypting and decrypting electronic documents with different keys (a public key and a private key). The public key is used for verifying the identity of a signer when the signer receives the digital signature. The private key is kept hidden and is used for the digital signature. A digital certificate includes a public key, a private key, signer information, and so on, which are issued by an authoritative third-party organization. Typically, electronic documents are signed digitally using a desktop computer or a notebook.
Therefore, what is needed is a system and method for digitally signing electronic documents which can digitally sign electronic documents using a mobile device such as a mobile phone.